AS a pioneering aviation engineer in the 1940s, James "Gerry" Gerrand designed some of the first distance-measuring equipment to improve aviation safety.

In the 1960s and 1970s, he guided civil aviation infrastructure planning in at least 10 Third World countries. Then, after retiring, he threw his energy into co-founding the Australian Skeptics and later founding, and for 15 years running, the Inflammatory Neuropathy Support Group.

James Hamilton Gerrand was born on May 29, 1919, in Newcastle, NSW, the sixth of seven children of journalists Andrew and Hattie (nee Graham) Gerrand. During the Depression, Andrew and Hattie lost their jobs and only three of their children were able to continue their education through to university, by winning scholarships - in Gerry's case, to Sydney Grammar.

He graduated from the University of Sydney in 1941 with first-class honours in science and engineering (electrical and mechanical). The CSIRO immediately recruited him into its radiophysics laboratories, where he spent the war years designing and installing top-secret radar systems.

In 1944-45, supervised by the physicist and inventor Dr E. G. "Taffy" Bowen, Gerrand designed prototype equipment that measured a plane's distance from a target aerodrome. His "simple to operate" 11-kilogram measuring equipment's specifications were adopted in Australia and by the International Civil Aviation Organisation (ICAO).

While at the CSIRO, Gerrand met WAAF officer Betty Cohen, a psychology graduate from the University of Sydney. They married in 1943. After nearly three years with Trans Australian Airlines in Sydney, in 1948 Gerrand joined the Department of Civil Aviation (DCA) and moved to Melbourne.

In 1953, the family moved to Port Moresby, where Gerrand worked as the superintending airways engineer for DCA. On returning to Melbourne in 1956, as superintending airways engineer for Victoria and Tasmania, his biggest project was planning Melbourne's new Tullamarine Airport.

He contributed his expertise to developing countries, and while still with the DCA he spent periods on loan to Nepal (in 1966) and Indonesia (in 1968). In 1973, he took a bigger plunge, joining the United Nations' ICAO, first as a project manager in Mogadishu, Somalia, for one year, then as a senior development officer at ICAO's headquarters in Montreal for a further six. After the UN's retiring age of 60 finished Gerrand's career in 1980, he and Betty returned to Melbourne.

In 1980, he co-founded the Australian Skeptics with Mark Plummer and Phillip Adams, tackling the commercial television shows that gave uncritical publicity to psychics, water diviners, and the "psychic surgeons" of the Philippines.

He was also national secretary of the Australian Humanists and a committee member of the Rationalist Society of Australia.

In 1990, Gerrand was diagnosed with CIDP (chronic inflammatory demyelinating polyneuropathy), which leads to loss of nerve communication with the feet and hands. On being told not much was known about the disease, Gerrand founded the Inflammatory Neuropathy Support Group of Victoria (the IN Group), and he and Betty worked to give information to people in Australia and overseas.

In 2002, Gerrand began a two-year campaign to alert health ministers to a shortage of Intragam, the blood-plasma product essential for treatment of CIDP and Guillain-Barre Syndrome.

When the authorities restricted Intragam to only those in life-threatening situations, he orchestrated a media campaign that caused the original policy to be restored.

Gerrand and Betty only stepped down from their work for the IN Group in 2006, when he found he was losing his memory to Alzheimer's. As the disease advanced, he retained his gentle sense of humour, his stoicism, his love of family - and his love of Mozart.

Gerry Gerrand is survived by Betty, his children, Peter, Rob, Jenny, Jeremy and David, and their partners, his seven grandchildren and his three great-grandchildren.